Uso de sais de boro no tratamento preservativo da madeira

Abstract

This research aimed to evaluate the effectiveness of a preservative solution based on boric acid and sodium tetraborate in wood treatment, as well as to determine the most efficient concentration. Test specimens measuring 2 × 2 × 5 cm were prepared from Eucalyptus urophylla, Eucalyptus camaldulensis × E. urophylla, Khaya ivorensis (African mahogany), and Pinus sp. The samples were subjected to a vacuum of 600 mmHg in two 30-minute stages, with a 40-minute interval between them to facilitate solution impregnation, using concentrations of 2%, 3%, 4%, 5%, and 6%. The treated material was then subjected to a colorimetric test using curcumin and a salicylic acid solution to assess preservative penetration. Subsequently, four distinct assays were conducted to evaluate treatment performance: a feeding-preference test and a forced-feeding test, both using termites, and two decay assays using brown-rot and white-rot fungi to assess resistance to wood-degrading organisms. The results showed that all solution concentrations were effective; therefore, the 2% concentration was identified as the most suitable, as it required less raw material while providing the same performance as higher concentrations.